Transcriptome based Identification of silver stress responsive sRNAs from Bacillus cereus ATCC14579.

Area of Science:

• Microbiology
• Molecular Biology
• Genomics

Background:

• Microbes adapt to environmental changes through metabolic and physiological adjustments.
• Small regulatory RNAs (sRNAs) play crucial roles in post-transcriptional gene regulation.
• Identifying novel sRNAs is essential for understanding microbial stress responses.

Purpose of the Study:

• To identify novel stress-responsive small regulatory RNAs (sRNAs) in Bacillus cereus ATCC 14579.
• To utilize microarray expression data (GSE26043) from silver nitrate (AgNO3) stress conditions.
• To develop and validate a computational model for sRNA discovery.

Main Methods:

• Analysis of intergenic region (IGR) expression from microarray data to predict sRNAs with >=2 fold change under silver stress.
• Computational prediction of sRNAs using sRNAscanner, focusing on rare promoter (Sigma 24, 28, 32, 54, 70) and terminator signals.
• Cross-validation of computationally predicted sRNAs with high-expression IGRs from microarray data.

Main Results:

• Prediction of 1512 sRNA-specific regions, resulting in 860 unique, high-scoring sRNAs with distinct promoters and terminators.
• Identification of 71 novel sRNAs under metal stress response, in addition to 14 previously reported sRNAs.
• Observation that some identified sRNAs possess multiple rare promoters, suggesting potential activation under various stress conditions.

Conclusions:

• A robust computational approach was established for identifying novel sRNAs from microarray data, applicable to other microbial systems.
• The study significantly expands the repertoire of known sRNAs in B. cereus, particularly those involved in metal stress response.
• The findings highlight the potential for sRNAs to be activated under multiple stress conditions, warranting further investigation into their mRNA targets and functional networks.